Temporal recognition of sperm autoantigens by IgM and IgG autoantibodies after vasectomy and vasovasostomy

Abstract

Temporal patterns of IgM and IgG autoantibodies to sperm proteins were studied by western blot analysis at intervals after bilateral vasectomy, vasectomy followed one month later by vasovasostomy, or sham operations. Responses were detected to eight major autoantigens at 21-23, 36, 41, 51, 57, 63, 68-71 and 75-83 kDa, by study of staining patterns of sequential serum samples from individual animals and by analysis of the incidence of reaction to each protein. The four lower molecular weight antigens (21-23, 36, 41 and 51 kDa) provoked mainly IgG responses. The strongly stained set of higher molecular weight antigens (57, 63, 68-71 and 75-83 kDa) tended to show more clearly defined temporal patterns of IgM followed by IgG response, including a high incidence of IgM antibody at the 2-week interval. Three of the larger peptides (57, 63 and 68-71 kDa) appeared highly immunogenic, since some reactions were detected even in sham-operated rats. The classical patterns of IgM and IgG antibody responses to the majority of the dominant sperm autoantigens are in accord with the hypothesis that vasectomy mimics immunization with spermatozoa. The high incidence of IgM antibodies in the earliest sample, taken 2 weeks after vasectomy, suggests that the initial immunizing event takes place within about a week after the operation. Vasovasostomy did not bring about a decrease in antisperm antibodies. Instead, some animals demonstrated an increased reaction to certain antigens after reversal of vasectomy, even though the vasovasostomies were anatomically successful.

PIP: The production of antisperm antibodies is common subsequent to vasectomy and antisperm antibodies frequently persist following the reversal of vasectomy. The number of such antibodies may even increase after vasovasostomy. Using adult male Lewis rats, the authors analyzed the dominant autoantigens which evoke IgM and/or IgG autoantibodies after vasectomy by western blotting (WB) methods, the temporal patterns of IgM and IgG autoantibodies to specific sperm proteins, and the influence of vasovasostomy upon IgM and IgG antisperm autoantibodies. The temporal patterns were studied by WB at intervals after bilateral vasectomy, vasectomy followed 1 month later by vasovasostomy, and fake operations. Responses were detected to 8 major autoantigens of 21-23, 36, 41, 51, 57, 63, 68-71, and 75-83 kDa through the study of staining patterns of sequential serum samples from individual animals and by analysis of the incidence of reaction to each protein. The 4 lower-molecular-weight antigens provoked mainly IgG responses, while the strongly stained higher-molecular-weight antigens showed more clearly defined temporal patterns of IgM followed by IgG response, including a high incidence of IgM antibody at the 2-week interval. The peptides of 57, 63, and 68-71 kDa seemed to be highly immunogenic, since some reactions were detected even in rats which received only a fake operation. Results support the hypothesis that vasectomy mimics immunization with spermatozoa, while the high incidence of IgM antibodies in the earliest sample, taken 2 weeks after vasectomy, suggests that the initial immunizing event occurs within approximately 1 week after the operation. Vasovasostomy caused no decrease in antisperm antibodies.